docs: def set_euk_hmm(self, args):
          'Set the hmm used by graftM to cross check for euks.'
          if hasattr(args, 'euk_hmm_file'):
              pass
          elif not hasattr(args, 'euk_hmm_file'):
              # set to path based on the location of bin/graftM, which has
              # a more stable relative path to the HMM when installed through
              # pip.
              setattr(args, 'euk_hmm_file', os.path.join(os.path.dirname(inspect.stack()[-1][1]),'..','share', '18S.hmm'))
          else:
              raise Exception('Programming Error: setting the euk HMM')